3 element lens info!

Hi Guys

This topic has cropped up a few times recently, so I thought Id just post a reference thread for the construction of a 3 element lens. The idea is simply to let people know how to re-build a 3 element lens, should they have forgotten which order and orientation the lenses fit into the barrel.



In the image above you can see that there are in fact only 2 glass elements! The arrow shows where two individual lenses are glued together forming 1 of the glass pieces. The double element goes in first with convex surface pointing down. Next comes the spacer followed by the thinner glass element, this too with the convex surface pointing down. Finally the lock ring is added to hold everything securely in place.

Hope this helps! :beer:

This is awesome. Thanks buddy!

This is awesome for a newb like me! Thanks!

awesome!! turns out i am (was) missing the smaller lens. I ordered a new 3 element and everything is back to normal.. actually it seems more powerful. do they make acrylic(plastic) lenses that are less efficient? It would seem that with the new glass lens i can burn stuff alot faster.. Not that burning stuff is what we do with these things ;P

grainde said:

Hi Guys

This topic has cropped up a few times recently, so I thought Id just post a reference thread for the construction of a 3 element lens. The idea is simply to let people know how to re-build a 3 element lens, should they have forgotten which order and orientation the lenses fit into the barrel.

In the image above you can see that there are in fact only 2 glass elements! The arrow shows where two individual lenses are glued together forming 1 of the glass pieces. The double element goes in first with convex surface pointing down. Next comes the spacer followed by the thinner glass element, this too with the convex surface pointing down. Finally the lock ring is added to hold everything securely in place.

Hope this helps! :beer:

Click to expand...

how would this thread onto the lens???
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are you trolling or serious? LOL..... the pointy end is the output, the threaded portion in the bottom where the lens assembly threads. I find it difficult to believe I am doing other than feeding you.

Alaskan said:

are you trolling or serious? LOL..... the pointy end is the output, the threaded portion in the bottom where the lens assembly threads. I find it difficult to believe I am doing other than feeding you.

Click to expand...

omg why does everyone think im a troll??? im new to this hobby that's all. all im trying to ask is when I do my next build id like to get this for the lens... I tried to figure out how to get the ring off the lens but it wouldn't come off. I wasnt sure if it just went right over the entire lens assembly. im sorry you think im trolling but im not. does the focusing ring just go into the cone or do I have to take the ring off?? that's all im trying to figure out

yes take the ring off! sometimes they get glued on to keep them from threading off.
The lens will then thread into the larger focus ring!

10fenny said:

yes take the ring off! sometimes they get glued on to keep them from threading off.
The lens will then thread into the larger focus ring!

Click to expand...

ok thanks, that's what I figured, it wont come off at all. I think its glued. ill just ask dtr if he glued it on.. thanks for the info

noobphaser215: You are talking about trying to remove the focus ring right? the focus ring is the silver piece on the right side of this picture right:



Just twist that off as best you can. If it's really stuck, wrap the threads in some plastic or paper and use some pliers. The paper/plastic will protect the threads from being damaged. Then to attach to the pointy focus ring above, you just screw the lens barrel in snugly.

Yuppers, that's what I was trying to say lol.. The actual ring. Thanks for the info. I'll be msging DTR tomorrow to see if he glued it on. Thanks again